Leveling up flintness does do a lot against the hits of Adam, but they seem to go to lvl 10 only.
Helmets are also a great help.

I was thinking maybe a mage setup would maybe work against this type of team.
They are not touched by Flavius or Herja and work well against tanks.

It is a bit of a shame we have no hero who attacks the entire backline.
Most Herjas are lower on HP. Could focus on taking her out first to at least make Adam not skill every round?